Hello, new guy here. Actually I've lurked on these forums quite a bit, but this is the first time I haven't been able to find and answer with the search tool. So I decided to sign up. Anyway, I've got a 69 chevy c10 truck and I'm planning to get one of those rear mount gas tanks that LMC sells to replace the behind the seat one that came out of it (what were they thinking?). The tank kit comes with everything but lines, wiring, and a filler tube + cap.

I'm looking for some advice on mounting the filler tube. I've seen people mount it behind the license plate on the rear bumper, but I can't find a kit for this anywhere. I've also seen them mounted in the bed, or under a panel in the bed, but I don't won't to go this route since if I'm hauling anything it could be in the way. Does anyone know where I could get a good filler tube kit? Any help or suggestions would be greatly appreciated. Thanks.